/****************************************************************************
 ** Modern Linbo GUI
 ** Copyright (C) 2020  Dorian Zedler <dorian@itsblue.de>
 **
 ** This program is free software: you can redistribute it and/or modify
 ** it under the terms of the GNU Affero General Public License as published
 ** by the Free Software Foundation, either version 3 of the License, or
 ** (at your option) any later version.
 **
 ** This program is distributed in the hope that it will be useful,
 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 ** GNU Affero General Public License for more details.
 **
 ** You should have received a copy of the GNU Affero General Public License
 ** along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ****************************************************************************/

#include "linbobackend.h"

#define LINBO_CMD(arg) QStringList("linbo_cmd") << (arg)

using namespace std;

LinboBackend::LinboBackend(QObject *parent) : QObject(parent)
{
    this->setState(Initializing);
    this->logger = new LinboLogger(this);
    this->config = new LinboConfig(this);
    this->autostartTimer = new QTimer(this);
    this->autostartTimer->setSingleShot(true);
    this->autostartRemainingTimeRefreshTimer = new QTimer(this);
    this->autostartRemainingTimeRefreshTimer->setSingleShot(true);
    this->autostartRemainingTimeRefreshTimer->setInterval(10);
    this->autostartElapsedTimer = new QElapsedTimer();
    this->currentOs = nullptr;

    // read start.conf
    this->logger->log("Starting to parse start.conf", LinboLogger::LinboGuiInfo);
    ifstream input;
    input.open( "start.conf", ios_base::in );

    QString tmp_qstring;

    while( !input.eof() ) {
        // *** Image description section ***

        // entry in start tab
        char line[500];
        input.getline(line,500,'\n');
        tmp_qstring = QString::fromAscii( line, -1 ).stripWhiteSpace();

        if ( tmp_qstring.startsWith("#") || tmp_qstring.isEmpty() ) continue;

        tmp_qstring = tmp_qstring.section("#",0,0).stripWhiteSpace(); // Strip comment
        if(tmp_qstring.lower().compare("[os]") == 0) {
            LinboOs* tmpOs = read_os(&input);
            if(!tmpOs->getName().isEmpty()) {
                this->operatingSystems.append(tmpOs);

                if(tmpOs->getAutostart() && this->currentOs == nullptr)
                    this->currentOs = tmpOs;

                // check if this is an additional/incremental image for an existing OS
                /* TODO unsigned int i; // Being checked later.
                for(i = 0; i < elements.size(); i++ ) {
                if(tmp_os.get_name().lower().compare(elements[i].get_name().lower()) == 0) {
                elements[i].image_history.push_back(tmp_image); break;
                }
                }
                if(i==elements.size()) { // Not included yet -> new image
                tmp_os.image_history.push_back(tmp_image);
                elements.push_back(tmp_os);
                }*/
            }
            else {
                tmpOs->deleteLater();
            }
        } else if(tmp_qstring.lower().compare("[linbo]") == 0) {
            read_globals(&input, config);
        } else if(tmp_qstring.lower().compare("[partition]") == 0) {
            LinboDiskPartition* tmpPartition = read_partition(&input);
            if(!tmpPartition->getPath().isEmpty()) {
                diskPartitions.append(tmpPartition);
            }
            else {
                tmpPartition->deleteLater();
            }
        }
    }
    input.close();

    this->logger->log("Finished to parsing start.conf", LinboLogger::LinboGuiInfo);
    this->logger->log("Loading global configuration", LinboLogger::LinboGuiInfo);

    // load global config
    QStringList command;
    // ascynchorons commands are logged to logger
    this->asynchronosProcess = new QProcess();
    connect( asynchronosProcess, SIGNAL(readyReadStandardOutput()),
             this, SLOT(readFromStdout()) );
    connect( asynchronosProcess, SIGNAL(readyReadStandardError()),
             this, SLOT(readFromStderr()) );

    // synchronos commands are not logged
    this->synchronosProcess = new QProcess();

    //  client ip
    this->config->setIpAddress(this->executeCommand(true, "ip"));

    // mac address
    this->config->setMacAddress(this->executeCommand(true, "mac"));

    // Version
    this->config->setVersion(this->executeCommand(true, "version").stripWhiteSpace());

    // hostname
    this->config->setHostname(this->executeCommand(true, "hostname"));

    // CPU
    this->config->setCpu(this->executeCommand(true, "cpu"));

    // Memory
    this->config->setRamSize(this->executeCommand(true, "memory"));

    // Cache Size
    this->config->setCacheSize(this->executeCommand(true, "size"));

    // Harddisk Size
    QRegExp *removePartition = new QRegExp("[0-9]{1,2}")    ;
    QString hd = this->config->getCache();
    // e.g. turn /dev/sda1 into /dev/sda
    hd.remove( *removePartition );
    this->config->setHddSize(this->executeCommand(true, "size", hd));


    this->logger->log("Finished loading global configuration", LinboLogger::LinboGuiInfo);

    // default select first OS if no other OS has been selected yet
    if(this->operatingSystems.length() > 0 && this->currentOs == nullptr)
        this->currentOs = this->operatingSystems[0];

    // triger autostart
    if(this->currentOs->getAutostart())
        this->executeAutostart();
    else
        this->setState(Idle);
}

// --------------------
// - Public functions -
// --------------------

void LinboBackend::executeAutostart() {
    this->autostartTimer->setInterval(this->currentOs->getAutostartTimeout() * 1000);
    this->autostartElapsedTimer->restart();
}

void handleAutostartTimerTimeout() {

}

void LinboBackend::shutdown() {
    this->executeCommand(false, "busybox", QStringList("poweroff"));
}

void LinboBackend::reboot() {
    this->executeCommand(false, "busybox", QStringList("reboot"));
}

bool LinboBackend::startCurrentOs() {
    LinboOs* os = this->currentOs;

    if(os == nullptr || this->state != Idle || !this->currentOs->getStartbutton())
        return false;

    this->setState(Starting);

    return true;

    this->executeCommand(
                false,
                "start",
                os->getBootPartition(),
                os->getRootPartition(),
                os->getKernel(),
                os->getInitrd(),
                os->getKernelOptions(),
                this->config->getCache()
                );

    return true;
}

bool LinboBackend::syncCurrentOs() {
    LinboOs* os = this->currentOs;

    if(os == nullptr || this->state != Idle || !this->currentOs->getSyncbutton())
        return false;

    this->setState(Syncing);

    this->executeCommand(
                false,
                "syncstart",
                this->config->getServer(),
                this->config->getCache(),
                os->getBaseImage()->getName(),
                os->getDifferentialImage()->getName(),
                os->getBootPartition(),
                os->getRootPartition(),
                os->getKernel(),
                os->getInitrd(),
                os->getKernelOptions()
                );

    return true;
}

bool LinboBackend::reinstallCurrentOs() {
    LinboOs* os = this->currentOs;

    if(os == nullptr || this->state != Idle || !this->currentOs->getNewbutton())
        return false;

    this->setState(Reinstalling);

    this->executeCommand(
                false,
                "syncr",
                this->config->getServer(),
                this->config->getCache(),
                os->getBaseImage()->getName(),
                os->getDifferentialImage()->getName(),
                os->getBootPartition(),
                os->getRootPartition(),
                os->getKernel(),
                os->getInitrd(),
                os->getKernelOptions(),
                QString("force")
                );

    return true;
}

bool LinboBackend::partitionDrive(bool format) {
    if(this->state != Root)
        return false;

    this->setState(Partitioning);

    QStringList commandArgs = QStringList(format ? "partition":"partition_noformat");
    for( int i=0; i < this->diskPartitions.length(); i++) {
        LinboDiskPartition* p = this->diskPartitions[i];
        commandArgs.append(
                    this->buildCommand(
                        p->getPath(),
                        QString::number(p->getSize()),
                        p->getId(),
                        QString((p->getBootable())?"bootable":"\" \""),
                        p->getFstype()
                        )
                    );
    }

    this->executeCommand(false, this->linboCmdCommand, commandArgs);

    return true;
}

bool LinboBackend::initializeCache() {
    if(this->state != Root)
        return false;

    this->setState(InitializingCache);

    QStringList commandArgs = this->buildCommand("initcache", config->getServer(), config->getCache());

    if( this->config->getDownloadType().isEmpty() )
        commandArgs.append(this->config->getDownloadType());
    else
        commandArgs.append("rsync");

    for(int i = 0; i < this->operatingSystems.length(); i++) {
        LinboOs* os = this->operatingSystems[i];
        commandArgs.append(this->buildCommand(os->getBaseImage()->getName(), os->getDifferentialImage()->getName()));
        /* TODO ?? for(unsigned int j = 0; j < os[i].image_history.size(); j++) {
          saveappend( command, os[i].image_history[j].get_image() );
        }*/
    }

    this->executeCommand(false, this->linboCmdCommand, commandArgs);

    return true;
}

bool LinboBackend::updateLinbo() {
    if(this->state != Root)
        return false;

    this->executeCommand("update", this->config->getServer(), this->config->getCache());

    return true;
}

LinboLogger* LinboBackend::getLogger() {
    return this->logger;
}

LinboConfig* LinboBackend::getConfig() {
    return this->config;
}

QList<LinboOs*> LinboBackend::getOperatingSystems() {
    return this->operatingSystems;
}

LinboOs* LinboBackend::getCurrentOs() {
    return this->currentOs;
}

void LinboBackend::setCurrentOs(LinboOs* os) {
    if(this->state != Idle || !this->operatingSystems.contains(os) || this->currentOs == os)
        return;

    this->currentOs = os;
    emit this->currentOsChanged(os);
}


double LinboBackend::getAutostartTimeoutProgress() {
    return this->autostartElapsedTimer->elapsed() / this->autostartTimer->interval();
}

int LinboBackend::getAutostartTimeoutRemainingSeconds() {
    return (this->autostartTimer->interval() - this->autostartElapsedTimer->elapsed()) / 1000;
}

// -----------
// - Helpers -
// -----------

QString LinboBackend::executeCommand(bool waitForFinished, QString command, QStringList commandArgs) {

    this->logger->log("Executing " + QString(waitForFinished ? "synchronos":"asynchronos") + ": " + command + " " + commandArgs.join(" "), LinboLogger::LinboGuiInfo);

    if(waitForFinished) {
        // clear old output
        this->synchronosProcess->readAll();

        synchronosProcess->start(command, commandArgs);
        synchronosProcess->waitForStarted();

        while( !synchronosProcess->waitForFinished(10000) ) {}
        return this->synchronosProcess->readAllStandardOutput();
    }
    else {
        asynchronosProcess->start(command, commandArgs);
        asynchronosProcess->waitForStarted();

        return "";
    }
}


void LinboBackend::readFromStdout() {
    QString stdOut = this->asynchronosProcess->readAllStandardOutput();
    QStringList lines = stdOut.split("\n");
    for(QString line : lines) {
        this->logger->log(line, LinboLogger::StdOut);
    }
}

void LinboBackend::readFromStderr() {
    QString stdOut = this->asynchronosProcess->readAllStandardError();
    QStringList lines = stdOut.split("\n");
    for(QString line : lines) {
        this->logger->log(line, LinboLogger::StdErr);
    }
}

LinboBackend::LinboState LinboBackend::getState() {
    return this->state;
}

void LinboBackend::setState(LinboState state) {
    if(this->state == state)
        return;

    this->state = state;
    emit this->stateChanged(this->state);
}

// Return true unless beginning of new section '[' is found.
bool LinboBackend::read_pair(ifstream* input, QString& key, QString& value) {
    char line[1024];
    if(input->peek() == '[') return false; // Next section found.
    input->getline(line,1024,'\n');
    QString s = QString::fromAscii( line, -1 ).stripWhiteSpace();
    key = s.section("=",0,0).stripWhiteSpace().lower();
    if(s.startsWith("#")||key.isEmpty()) {
        key = QString(""); value = QString("");
    } else {
        value=s.section("=",1).section("#",0,0).stripWhiteSpace();
    }
    return true;
}

bool LinboBackend::toBool(const QString& value) {
    if(value.startsWith("yes",false)) return true;
    if(value.startsWith("true",false)) return true;
    if(value.startsWith("enable",false)) return true;
    return false;
}

LinboOs* LinboBackend::read_os(ifstream* input) {
    LinboOs* os = new LinboOs(this);
    QString key, value;
    while(!input->eof() && read_pair(input, key, value)) {
        if(key.compare("name") == 0) os->setName(value);
        else if(key.compare("description") == 0)  os->setDescription(value);
        else if(key.compare("version") == 0)      os->setVersion(value);
        else if(key.compare("iconname") == 0)     os->setIconName(value);
        else if(key.compare("image") == 0)        os->setDifferentialImage(new LinboImage(value, os));
        else if(key.compare("baseimage") == 0)    os->setBaseImage(new LinboImage(value, os));
        else if(key.compare("boot") == 0)         os->setBootPartition(value);
        else if(key.compare("root") == 0)         os->setRootPartition(value);
        else if(key.compare("kernel") == 0)       os->setKernel(value);
        else if(key.compare("initrd") == 0)       os->setInitrd(value);
        else if(key.compare("append") == 0)       os->setKernelOptions(value);
        else if(key.compare("syncenabled") == 0)  os->setSyncButton(toBool(value));
        else if(key.compare("startenabled") == 0) os->setStartButton(toBool(value));
        else if((key.compare("remotesyncenabled") == 0) || (key.compare("newenabled") == 0))   os->setNewButton(toBool(value));
        else if(key.compare("defaultaction") == 0) os->setDefaultAction(os->startActionFromString(value));
        else if(key.compare("autostart") == 0)   os->setAutostart(toBool(value));
        else if(key.compare("autostarttimeout") == 0)   os->setAutostartTimeout(value.toInt());
        else if(key.compare("hidden") == 0)   os->setHidden(toBool(value));
    }
    return os;
}

LinboDiskPartition* LinboBackend::read_partition(ifstream* input) {
    LinboDiskPartition* partition = new LinboDiskPartition(this);
    QString key, value;
    while(!input->eof() && read_pair(input, key, value)) {
        if(key.compare("dev") == 0) partition->setPath(value);
        else if(key.compare("size") == 0)  partition->setSize(value.toInt());
        else if(key.compare("id") == 0)  partition->setId(value);
        else if(key.compare("fstype") == 0)  partition->setFstype(value);
        else if(key.startsWith("bootable", false))  partition->setBootable(toBool(value));
    }
    return partition;
}

void LinboBackend::read_globals( ifstream* input, LinboConfig* config ) {
    QString key, value;
    while(!input->eof() && read_pair(input, key, value)) {
        if(key.compare("server") == 0) config->setServer(value);
        else if(key.compare("cache") == 0)  config->setCache(value);
        else if(key.compare("roottimeout") == 0)  config->setRootTimeout((unsigned int)value.toInt());
        else if(key.compare("group") == 0)  config->setHostgroup(value);
        else if(key.compare("autopartition") == 0) config->setAutopartition(toBool(value));
        else if(key.compare("autoinitcache") == 0) config->setAutoInitCache(toBool(value));
        else if(key.compare("autoformat") == 0) config->setAutoFormat(toBool(value));
        else if(key.compare("backgroundfontcolor") == 0) config->setBackgroundFontcolor(value);
        else if(key.compare("consolefontcolorstdout") == 0) config->setConsoleFontcolorStdout(value);
        else if(key.compare("consolefontcolorstderr") == 0) config->setConsoleFontcolorStderr(value);
        else if(key.compare("usemulticast") == 0) {
            if( (unsigned int)value.toInt() == 0 )
                config->setDownloadType("rsync");
            else
                config->setDownloadType("multicast");
        }
        else if(key.compare("downloadtype") == 0) config->setDownloadType(value);
    }
}